Dmitry, Thanks, I understood. I have no objection.
Yasumasa On 2016/03/23 20:51, Dmitry Samersoff wrote: > Yasumasa, > > We have at least two problems with explicit setting of IP_MULTICAST_IF > that I can reproduce in-house.[1] > > Source address of IP packet should match the interface we are using > and network configuration can be changed while Java app is running i.e. > after the point we are setting interface flags. > > So existing code is incorrect, and I decide to remove it. > > If we need to reliably send broadcast to all available interfaces, > code have to be more complicated than just setting IP_MULTICAST_IF on > jdp start. > We probably need to check the state of available interfaces > periodically and launch separate JdpBroadcaster for each interface. > > I'm not sure we should add such complication to Jdp. > Sorry! > > * * * > 1. Below is Linux/tcpdump output in one of test configurations: > eth0 192.168.0.77 connected to LAN, wlan0 172.16.2.100 is not connected > to anything. > > *Default settings:* > > dooku:hs-rt#tcpdump -n -i eth0 port 7095 > > IP 192.168.0.77.35874 > 224.0.23.178.7095: UDP, length 262 > > dooku:hs-rt#tcpdump -n -i wlan0 port 7095 > > <no packets> > > *IP_MULTICAST_IF set explicitly for both eth0 and wlan0* > > dooku:hs-rt#tcpdump -n -i eth0 port 7095 > > IP 172.16.2.100.44921 > 224.0.23.178.7095: UDP, length 262 > > dooku:hs-rt#tcpdump -n -i wlan0 port 7095 > > IP 172.16.2.100.42919 > 224.0.23.178.7095: UDP, length 262 > > -Dmitry > > > > > On 2016-03-23 02:18, Yasumasa Suenaga wrote: >> Hi Dmitry, >> >> Does your change work on Linux multi-homed environment? >> The code which you remove is added at JDK-8057556. >> >> >> http://mail.openjdk.java.net/pipermail/serviceability-dev/2014-September/015504.html >> >> DiagramChannel which is used in JDPBroadcaster tries to send JDP packet >> through all "UP" NICs. >> However, NIC which is controlled by NetworkManager seems to be still "UP" >> when ifdown command is executed. >> (It seems to be removed IP address from NIC only.) >> >> I cannot check your change because I destroyed environment for reproduce. >> Did you check your change on Linux multi-homed (and NetworkManager is active) >> environment? >> >> >> Thanks, >> >> Yasumasa >> >> >> On 2016/03/22 20:51, Dmitry Samersoff wrote: >>> Everybody, >>> >>> Please review the fix: >>> >>> http://cr.openjdk.java.net/~dsamersoff/JDK-8151444/webrev.01/ >>> >>> Removed code attempts to set IP_MULTICAST_IF to enforce sending of JDP >>> packets to all available interfaces. It doesn't work on some multi-homed >>> windows configurations. >>> >>> Also fixed minor bug in testcase. >>> >>> -Dmitry >>> >>> >>> > >
